Centrifugal blower



Feb. 6, 1951 J, E 0| |PHANT 2,540,136

CENTRIFUGAL BLOWER d July 24, 1946 INVENTORI JOHN E. OLIPHANT mama Feb.a, 1951 UNITED STATES PATENT- OFFICE 'i..,";';?';;I;.i.':.2.:.ft......

BOIaims. (01.230-13!) My invention relates to centrifugal blowers, andmore particularly to impellers for the same, and one object is toprovide an impeller whose blades are extended with chambers efiective toseparate the radial air currents generated by the impeller and minimizetheir tendency to develop back pressure.

A- further object is to interconnect the impeller blades in a manner toform a continuous undulating wall which renders the blades extremelyrigid without complicating the construction of the impeller.

Another object is to provide the impeller with a series of inter-bladechambers which face alternately on opposite sides, each chamberincreasing in capacity in radial direction and promoting the passage ofa greater volume of air to the zone of discharge without'a greater powerrequirement.

A still further object is to design the novel impeller in a manner to becast or pressed in one piece of metal or plastic material, making its aconstruction simple and its manufacture economical.

With the above objects in view, and any others which may suggestthemselves from the description to follow, a better understanding of thesimple,'smooth-and economical to produce. Furinvention may be had byreference to the accompanying drawing, in which- Fig. 1 is a sectionalview, showing the impeller installed;

' Fig. 2 is a perspective view of the impeller; and Figs. 3 and 4 aresimilar views of modifications. In accordance with the foregoing,specific reference to the drawing indicates a typical centrifugal blowerhousing at I 0, it being understood that such housings are open aroundthe center shaft II for the entrance of air.

The improved impeller i formed as a disc If in the central region, suchdisc having an opening 93 to receive the shaft I i and suitable means(not shown) are employed to secure the disc I! rigidly on the shaft in aposition midway between the side walls of the housing.

' The disc I! is extended radially with a series of blades l4 directedtransversely of the path of impeller rotation, the form of each bladebeing that of an isosceles triangle with its vertex meeting theperiphery of the disc II. The blades are connected on alternate sides bywalls I,

creating a rotary series of chambers I which open on alternate sides ofthe impeller.

The construction just described facilitates the formation of theimpeller by casting or pressther, the formation of the chambersseparates the air currents entering into the zone of the blades so thatthese currents do notconfiict or overlap to create back pressure.Further, the outward deflection of the walls I! fromthe plane of thedisc I! increases the capacity of the chambers it, promotingthe'passageof a greater volume of air without requiring a corresponding increase inthe power to drive the impeller. Further, the chambers operate to leadthe incoming air currents radially, turbulence and slippage. Finally, itis apparent that the impeller is a compact unit whose plain surfacepromotes the passage of air currents with a negligible friction factor.

While Fig. 1 shows the main or preferred form of the impeller, it willbe apparent that the same is susceptible of minor changes ormodifications. Thus, Fig. 2 shows a modification wherein the blades llare inclined from the periphery of the disc I2, while Fig. 4 shows theblades l8 and walls is inclined and curved in s-fashion. Thesemodifications may retain or vary the mechanical efllciency of theimpeller while lending the same more attractive form. However, they donot change or depart from the principle of the invention as covered inthe appended claims. I claim:

1. An impeller for centrifugal blowers comprising a. disc forming acentral portion, a series of blades extending radially of the disc inplanes transverse to the path of blade rotation and wallsinterconnecting the side edges of the blades in alternate succession,said walls inclining outwardly of said disc. V

2. An impeller for centrifugal blowers comprising a disc forming acentral portion, and a series of blades extending radially of the discin planes transverse to the path of blade rotation, the blades being oftriangular form with one angle meeting the periphery of the disc, andwallsconnecting the sides of the blades in alternate succession to formchambers expanding in capacity in radial direction.

3. An impeller for centrifugal blowers comprising a disc forming acentral portion of a series of blades extending radially of the disc inplanes transverse to the path of blade rotation, and inclined wallsinterconnectingthe blades to form an undulating blade unit around thedisc, said inclined walls forming three-sided chambers expanding incapacity in radial direction.

4.- The structure of claim 3, said unit being ing in one piece, makingthe impeller extremely integral with the disc.

opposite sides of said disc, and blades transversely 5 connected to saidwalls to form a rotary series of three-sided chambers. i

6. The structure of claim 5, said walls being curved in substantiallyS-taahion.

JOHN E. OLIPHANT. 10

REFERENCES CITED The following references are of record in the file 0!this patent:

Number Number 4 UNITED STATES PATENTS Name Date Morcur Apr. 19, 1938Norln July 16, 1940 Sheldon June 20, 1944 FOREIGN PATENTS Country DateSwitzerland Apr. 1, 1942

